In a mobile communication system, if a physical layer is based on a TDD standard, uplink and downlink communications between a base station and a mobile station adopt different time slots of a same frequency channel (i.e., a carrier) to separate receiving and transmitting channels in terms of time, that is to say, the base station sends a signal to the mobile station during a time period and the mobile station sends a signal to the base station during another time period.
Along with the successful commercialization of a Time Division-Synchronous Code is Division Multiple Access (TD-SCDMA) technology and the trial commercialization of a Time Division Duplexing Long Term Evolution (TDD-LTE) technology, a user terminal (i.e., User Equipment (UE)) whose physical layer is based on the TDD standard is more and more popular. The architecture of a system based on the TDD standard is shown in FIG. 1; a subscriber accesses to the Internet through a UE to operate an application program based on Transmission Control Protocol (TCP)/Internet Protocol (IP); the UE interacts with a network side through a data packet based on the IP and Packet Data Convergence Protocol (PDCP) and can access various network resources to meet the requirements of study, jobs and living.
During the networking of an operator, uplink and downlink time slots based on the TDD can be dynamically adjusted and a subscriber needs more downlink data, so that the operator generally configures more transmission time slots than receiving time slots at the network side, which results in a high data download speed and a low data upload speed as for the user experience. Generally, during file downloading through Point to Point (P2P) software, a subscriber also performs file uploading at the same time, which will cause large uploading flow, so the data uploading of the UE becomes the bottleneck at the moment. The P2P software generally performs transmitting based on the TCP, and at the TCP layer, the UE needs to return an acknowledgement (ACK) type control packet every time it receives a TCP data packet from the network side. Each IP and TCP data packet has a packet header of 20 bytes respectively, while an Maximum Transmission Unit (MTU) is generally 1,500 bytes, which means at least 40 bytes of uploading data will be generated every time 1,500 bytes of data are downloaded from the network side; that is to say, when the downlink bandwidth for the subscriber is 1024 bytes, the uplink bandwidth is at least 27 k bytes. However, the receiving time slots configured for the network side are limited during actual networking, i.e., the uplink and downlink are not symmetrical, therefore, in case of large uploading flow of the UE, particularly when multiple application programs concurrently access a network, the application programs of the network side will be in a waiting state because of failing to timely receive the acknowledgement packet of the UE, thereby causing the idleness of an air interface and reducing the downlink capability of the network.